1. Field Of The Invention
The present invention is related to surgical suction and irrigation/lavage apparatus and methods, in particular those used for intraoperative gastric and bowel decompression to alleviate distension when the bowel is obstructed.
2. Related Art
Intestinal decompression has become an important procedure in abdominal surgery. In patients with small bowel obstruction (due to adhesions, tumors, hernias, etc.) and paralytic ileus there is an accumulation of ingested fluid, secretions and intestinal gas within the gastrointestinal tract. These produce distention of the intestine. Because of intestinal stasis, rapid intraluminal bacterial proliferation occurs. Normally, the small intestine contains very small quantities of bacteria and may be almost sterile. This distention and stasis has a profound effect on surgical results.
Any violation of bowel integrity significantly increases the likelihood of a postoperative intra-abdominal and wound infection due to the high risk of intra-operative contamination with postoperative enteric or anastomotic leak.
Bowel distention and increased intraluminal pressure inevitably impairs circulation to the bowel. This vascular compromise, along with intraluminal contamination can disrupt healing anastomoses and may lead to peritonitis.
The intraluminal fluid which contains toxic material is absorbed from the gastrointestinal tract. This produces systemic effects. Patients with intestinal distention have a high risk of postoperative motility disorders and prolonged post-operative ileus which greatly worsens the post-operative prognosis.
In patients with a distended bowel, intraoperative manipulations and abdominal closure are greatly impeded. In these patients it is essential to decompress the distended bowel to prevent intra-operative and post-operative complications. There is general consensus that in the surgical management of bowel obstruction, distention of the intestine requires proper attention.
Decompression of the bowel may be performed via enterotomy (open) or by "closed" techniques. Open methods entail the performance of enterotomy and/or enterostomy. Such techniques carry a high risk of intra-operative contamination in the abdominal cavity and the ability to perform adequate decompression throughout the obstructed bowel is effectively limited to the proximity of the "opened" areas only. "Closed" methods of decompression are carried out without violation of bowel integrity and require insertion of the intestinal tube into the gastrointestinal tract transnasally, orally, or through the anal canal.
The use of different catheters for nasointestinal decompression has long been known in the prior art. Some tubes are designed to be emplaced into the small bowel during the surgery and are provided with pairs of inflatable balloons which facilitate the manual manipulation of the catheter through the small intestine. C. Grassi, U.S. Pat. No. 5,078,701, describes an intestinal catheter which may be inserted into the gastrointestinal tract by use of a guide wire without surgery. A tip opening is connected to a feeding lumen and allows nutritive material to flow into the small intestine. Gastric openings located near the middle of the catheter and connected to the suction lumen permit aspiration of gastric content.
Such tubes are somewhat effective in carrying out intestinal decompression in pre-operative and post-operative periods. However, there is often a need to perform rapid and effective bowel decompression during surgery. Existing tubes fail to intubate the gastrointestinal tract effectively during surgery.
The gastrointestinal tract comprises the mouth, the esophagus, the duodenum, the small intestine and the large intestine. The gastroduodenal part of the gastrointestinal tract contains several regions of angulation and curvature. The pyloric part of the stomach contains a thick layer of muscles which are aggregated into the annular pyloric sphincter that contracts intermittently. The duodenum is curved in an incomplete circle and frequently shows variations in configuration. These portions of the gastrointestinal tract have traditionally been considered to be difficult to negotiate and frequently lead to technical difficulties and failure to emplace the tube into the small bowel.
Existing tubes are subject to frequent coiling and kinking, which create difficulties in manipulation and require of the surgeon special skill and dexterity. Even when the tube is emplaced in the small bowel, the construction and technical properties of currently available tubes do not allow a loaded small bowel to be cleansed to a desirable degree. Specifically, their small internal diameters have small suction openings and hence reduced cross-sectional areas that prohibit effective decompression within a reasonable time and do not avoid tube plugging by the bowel wall, or clogging and obstruction by the bowel wall and enteric content.
Existing medical suction devices (aspirators) are of two types: (1) continuous, and (2) intermittent. Continuous suction devices often become plugged with debris and organ tissues, causing inefficient evacuation of gas and fluid. Intermittent suction devices are regulated by thermotic or timing valves which shut off a suctioning phase and/or turn on an injection phase. Both methods of suctioning frequently fail to work satisfactorily. Timing valves shut off the suctioning phase after a pre-set time. Such systems cut off suction even when cessation is not required. Conventional systems may occlude after a certain period of time regardless of any other factors, such as intrinsic pressure. There is a need for a device which temporarily arrests suction only when the organ, cavity or space which needs to be decompressed, is empty and irrigates or vents the tube automatically only when there is a demand and effectively prevents an obstruction of the tube between the decompressed space and the suction device. If suction were to continue at that point, patients may develop serious or life-threatening complications.